Wireless communication systems of various kinds are known in the art. Many such systems support power saving strategies as used with mobile stations to aid in extending the effective operating time of a portable device. For example, some mobile stations can support multiple modes of operation wherein the different modes of operation have varying levels of characteristic power consumption associated therewith. By working in concert with one another, the communication system can facilitate the use of reduced power consumption modes of operation by the mobile station when and as appropriate.
For example, some communication systems (such as CDMA2000 3GPPP2 EVDV rel D and others) support an active mode of operation, a dormant mode of operation, and a semi-dormant mode of operation. The exact meaning of these concepts and the characterizing behaviors that define them can and will vary from system to system, of course, but in general, an active mode of operation tends to characterize the operational state of a mobile station when that mobile station is actively using an acquired communications channel to support normal communications (by transmission, reception, or both). Similarly, a dormant mode of operation tends to characterize the operational state of a mobile station when that mobile station is without an allocated communication channel (though other related capabilities, such as PPP functionality and the ability to communicate through common channels, may be nevertheless present) (for present purposes, it will be presumed that the concept of “dormant” subsumes both “dormant” and “idle” states as those terms are otherwise often understood by those skilled in this art).
A semi-dormant mode of operation comprises a more recently recognized operational state and generically represent a mode of operation that lies, functionally and/or operationally, between whatever comprises an active mode of operation and a dormant mode of operation in a given system. For example, in at least one system, the semi-dormant mode of operation is largely characterized by a lack of an allocated bearer channel but where the platform nevertheless continues to receive (or provide) periodic RF environment triggered system updates on a common channel such that the system can immediately effect channel assignment for the target without needing to page the target first in order to ascertain its RF environment.
Such a mobile station can aid in reducing system resource requirements by moving from an active mode of operation to a semi-dormant mode of operation while preserving an ability to relatively quickly resume active status as the semi-dormant-to-active transition can usually be accomplished more quickly than the change from dormant to active status.
While such multiple-state mobile stations can operate in a manner than benefits both the mobile station and the communication network itself, there are operating conditions that can lead to worsened, rather than improved, operating conditions. For example, a mobile station that exhibits or experiences high mobility while in a semi-dormant mode of operation will typically make frequent use of system communication resources to update the network with respect to its presently perceived reception conditions. Such high-mobility-instigated updating behaviors are, of course, often similar or identical to the same behaviors exhibited by a mobile station when undergoing high mobility while in an active mode of operation, except that this communication is over a common channel and thus is typically less tightly power controlled. This is not to say, however, that such high mobility-related behaviors have an equal overall network/user impact. In fact, the system impact varies considerably as between these two modes of operation.
During an active mode of operation, a mobile station already has an allocated communication resource, which is typically power controlled or rate controlled. Mobility-related updates therefore typically represent little increased consumption or system cost; that is, once a mobile station has an allocated channel, the existence or absence of frequent update transmissions, largely becomes irrelevant. During a semi-dormant mode of operation, however, the mobile station will not have access to a constantly allocated channel. Instead, the mobile station will be competing with other mobile stations for use of a potentially scarce common communication resource to effect its update transmissions. This can lead in many instances to undue loading of such resources.
Attempts to ameliorate such concerns are often hampered further by a frequent design requirement to spare the user from widely fluctuating user experiences. Therefore, a solution that seeks to address the high-mobility-based problems noted above must also usually not, at the same time, unduly lead to an unacceptable increase in system access time.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. It will also be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study except where specific meanings have otherwise been set forth herein.